Molding machine



J 1940- J. FLAMMANG ET AL momma momma Filed July 20, 1936 2 Sheets-Sheet1 June 11, 1940. FLAMMANG 2,204,407

MOLDING MACHINE Filed July 20, 1936 2 Sheets-Sheet 2 Patented June 11,1940 MOLDING nmcumn John Flammang and Percy L. Bowser, St. Louis, Mo.,assignors to The Sterling Corporation, St. Louis, Mo., a corporation ofDelaware v Application July 20, 1936, Serial No. 91,456

Claim.

This invention pertains to molding machines and more particularly to amachine for molding trunk pistons such as are used in internalcombustion engines. 7 5 One of the object s'in this invention is toprovide a machine by means of which pistonsmay be cast with improvedaccuracy and in such a manner that inaccuracies may be more easilydetected.

Another object is to provide a machine whereby the various sections ofmold and core may be separated and reassembled by operation of themachine so that when reassembled the various parts will be accuratelypositioned with respect to one another so as to form a true casting.

Another object is to provide improvements in the gate structure wherebythe pouring operation may be so improved as to provide better assurancefor sound castings. I v

Another object is to provide automatic mechanism for operating sectionalmolds and cores which will operate rapidly and accurately and which willbe safeguarded against mistakes of the operator.

Further objects will appear from the following. description taken inconnection with the ac companying drawings in which:

Figure l is a front view of a molding machine embodying this invention,

Figure 2 is a side view of Figure 1, Figure 3 is a top view of the moldcap. Figure 4 is a bottom view of the cap shown in Figure 3,

Figure 5 is a section on line 5-5 of Figure 3, Figure 6 is a detail ofthe drag block, Figure 7 is an enlarged detail of Figure 1, Figure 8 isa detail of the safety lock; and Figure 9 is a longitudinal sectionalview of a defective piston casting.

Referring now to the drawings I designates a supporting frame in whichis mounted upon trunnions 2 a supporting bracket 3 which in-turn carriesa horizontally extending base 4. Mounted on the base 4 is a piston moldcomprising 45 a pair of separable sections 5 surmounted by a mold cap 5,also sectionalized so as to open with the sections 5. Mounted inthe base4 are upper and lower locating rings I and 8 respectively in which thecore for the mold is mount- 50 ed. In the machine illustrated the coreis made up of three sections, namely a center section 5 and two sidesections III. The side sections ID aremounted in suitable channels inone of the locating-rings I or 8 so that when the center section 9 iswithdrawn downwardly the side sections may be moved inwardly into thespace vacated by the section 5; v

In order to render the side mold sections 5 slidable upon the base 4,there is provided for'each section 5 a carrier or angle plate H.-Suitable 6 guides it are provided to guide the carriers i I so that themold sections 5 will move toward and away from each other in a'straightline. Mounted at each end of the base 4 is a-fluid pressure cylinder l3havinga piston'rod ll connected to 10 the carrier ll so as to move thesame back and forth in accordance with the fluid pressure introducedinto the cylinder It. The piston rod H is releasably' connected tolthecarrier II. In order to make such connections the carrier is 15 providedwith four upstanding posts i5 spaced laterally of the carrier so as topermit the pasfsage therebetween of the rod I4 and nuts l6 thereon, andspaced longitudinally so as to receive therebetween 'a drag block II.The rod i4 20 has mounted thereon a collar II which is clamped inadjusted position upon the rod It by means of the nuts l6 which'providestops for the block l1. The drag block I1 is provided with a notch l9arranged to fit over the collar l8. By propg5 erly positioning thecollar l8 between the posts l5 and then slipping the drag block l'l overthe collar. between the posts. a connection is established between therod I4 and the carrier II, V

which provide respectively driving and driven 30 members with which theblock I1 is only loosely engaged, This connection is easily broken orreleased by simply removing the block I! without disturbing any otherelement of the connections, between the power device l3 and the mold 35section.

Mounted on the lower end of the bracket 3 is a fluid pressure cylinder20 having a piston rod 2| upon the upper end of which the center coresection 9 is mounted. Suitable means not shown are providedforcontrolling the admission of fluid pressureto the cylinders l3 and 20in proper order so as to draw back the mold sections 5 and towithdraw-the center core section 5 downwardly. The side core, sectionsll are mounted in a guide passages 22 in one or the other of the rings 1and 8 so" that they may be moved inwardly of the mold into the spacevacated by the section 5 and in a rectilinear-path so as to move clearof the interior portions of the casting without 0 danger of marring thesame. This movement ot the side core sections may be accomplishedmanually by the operator by means of handles 25 suitably connected tothe core sections.

In order to prevent the side sections II from cleared the space betweenthem,

.ing mechanism is suitable sockets 25 in sectionsllo. Each pin 24 iscarried by a block 26 adjustably' mounted upon a vertically slidable rod21. Each rod 21 may be guided in a suitable bracket 28 mounted on thebracket 3 and a spring 23 engaging the bracket 28 the block 23 serves tourge the rod 21 upwardly. This upward movement is arrested by engagementof its upper end with the top plate 30 of the bracket 3. The two rods 21are joined at their lower ends by a cross member 3| having a perforation32 at its center through which the piston rod 2| may pass. The rod 2|slides freely through the perforation 32 so that when it movesdownwardly to withdraw the center section 3, at the lower extremity ofits movement and after the section 3 has cleared the two side sections[0, a head 33; adjustable on the rod 2|, engages the cross-member 3|,drawing it downwardly and thereby withdrawing the pins 24 from thesockets 25 and releasing the side sections l3 for inward movement tofree the casting. The lower ends of the side sections ID are beveledoutwardly as shown at '34 so that incase the side sections should stillbe in collapsed position when the center section 3 starts its upwardmovement to its casting position, the

' beveled surfaces 34 may serve as cam surfaces to cause the section 3to force the sections I0 outwardly as it rises. As soon as the section 3begins to rise the head 33 releases the cross-member 3|, whereupon thespring 23 returns the pins 24 to locking position and causes them tosnap into the sockets 25 as soon as the sections l3 have been movedoutwardly.

In order to locate the several core sections more accurately withrespect to each other the center section! is provided with a pair ofguide pins 35 providing registering keys engageable in guide grooves 36in the side sections III. This serves to prevent lateral shift of theseveral sections with respect to one another.

The gate for pouring is placed in the mold cap 8 which, as has alreadybeen stated, is divided into half sections one of which is mounted uponeach of the mold sections 5 so that the cap Ii is divided and separatedto free the sprue when the mold is opened. Several forms of gates may beused in accordance with this invention. The cap 6 may be provided with asingle gate 31, flared at its outer end and more restricted in crosssection where it enters the mold matrix. As many piston castings areprovided with a reinforcing rib extending across the inside of thepiston head the core sections must be provided with a groovecorrespondingly positioned so as to form this rib. As the piston is castwith its head up, if the gate is placed in the center of the head themolten metal must be poured directly into this groove in the core. Therepeated pouring of very hot metal into this groove causes the metal toflow into the mold along the groove rather than over the head of thepiston core. This tends to concentrate the flow of highly heated metalcontinually along one particular part of the core so that this part isliable to be overheated and tends to become corroded at the point ofimpact of the molten metal. In accordance with this invention the gate31 is shifted laterally. The amount of shift need be only sufficient sothat when the metal is poured into the the guide portions of the gate itwill not flow directly into the center groove in the core but will missthat groove and flow over the head of the core and into the body of thepiston matrix. By slightly tilting theentire machine on its trunnions 2toward the side toward which the gate 31 is shifted the eiIect'will beto throw the incoming metal rearwardly and this helps to avoid pouringthe metal into the groove in the core.

While the casting process may be carried out to advantage with only asingle gate 31, this invention also contemplates providing a separategate 38 so placed so as to enter the mold matrix close to one sidethereof, This gate is used in addition to the gate 31.. As will be seenfrom Figure 3 the gate 38, at its inlet, is flared or extended in aradial direction with respect to the matrix so as to render it moreconvenient to insert the snout of the ladle in pouring the metal. Asseen inFigure 4 however, which shows a bottom view of the cap 6, thegate 38 is flared or extended in a direction circumferential to the moldmatrix. This enables the incoming stream of metal to spread sidewisetoward both sides of the matrix. At an intermediate position between theinlet and outletends of the gate 38 its cross section is practicallycircular and somewhat restricted as compared with the gate 31. When bothof these gates are used the gate 31 really acts as a riser. The metali'spoured in at the gate 38 and, after filling the matrix, the surplusmetal rises in the gate 31. -It will be noted that in this case themetal which rises in the gate 31 has come up from the mold and istherefore at about the same temperature as the metal of the pistonheadinstead of being at a high temperature such as that of the metal inthe'ladle. Accordingly, the high temperature metal fresh from the ladleis held in a small gate 38 while a considerable volume of metal is heldin the riser 31 but at a lower temperature. It will be seen that thisarrangement enables these parts to cool down to solidificationtemperature much more quickly than if the entire mass of metal in thegate 31 were at the ladle temperature. Accordingly, the setting of theentire casting is hastened and the work can be carried out much morerapidly as it is not necessary for this extra volume of metal to cooldown through such a great range of temperaturebefore the casting can beremoved.

In order to insure that when the mold sections 5 are closed they willtake position concentric with the core one or more abutments 33 areprovided on the ring 1, a corresponding recess being formed upon thesection 5 so that when the mold sections are closed they are positionedby engagement with the abutment 33. As these abutments are located uponthe same plate in which the core sections are located the mold sectionswill be accurately positioned concentric with the core so that the innersurface of the oasting will be concentric with the outer surfacethereof., In order to provide means for showing on the castings whetheror not the mold has been accurately closed and located by the abutment39 or whether there is an eccentricity of the exterior of the castingsurface with respect to the interior thereof, the mold sections 5 areprovided on the inner surface thereof with one or more prints 40 inorder to form upon the casting a tell-tale impression 4|. If the moldsections 5 are properly positioned the tell-tales 4| will be equidistantfrom the axis of the interior bore of the casting. Accordingly, when theouter I will be unequally distant from the aids and upon turning thecasting one will be removed before the other,

Figure 9, illustrates a casting 'made with the 10 mold sectionsimproperly located so that the outer. surface is not concentric with theinner surface. The dotted lines a represent the surfhce of the cylinderto which the casting is machined.

This cylinder, which has a radius R, is concentric 16 with the axis C.The casting is usually located in the lathe by means of its innersurface having a radius RI with respect tothe axis 0. Accordingly, thecylinder A-A will be concentric with this inner surface. It will benoted that the tell- D tale 4| on the left hand side of Figure 9 is onlypartly cut away by the turning operation while the one on the right handis entirely removed. Upon inspection of the turned casting the presenceof only one tell-tale will indicate a defective is casting. Theimpression 4| may be of anydesired shape as for instance a conicalimpression or one of spherical form will decrease in size as it isturned off so that thedegree of eccentricity may be indicated by thesize of the tell-tale re- ;o, maining.

In the operation of this machine the same may be set upright on itssupport I as illustrated in Figure 2 or it may be tilted on thetrunnions 2. With the mold sections 5 closed and the core 3 sections inassembled relation within the mold as shown in Figure 1, the operator,by means of a suitable ladle takes a charge of molten metal from asuitable supply, and inserting the snout of the ladle into the inlet ofthe gate 38, pours 40 the charge of metal into the mold until the metalrises in the riser 31 as described. In case only one gate 31 is used themetal is poured in at said gate and as the latter is displaced laterallyfrom the axis of the mold matrix, the

45 metal flows in laterally of the center of the core and flows over thetop of the core and down into the lower portion of the matrix whichforms the piston skirt. When the mold is full the metal rises in thegate 31 and the pouring is discon- 50 ti'nued when said gate ispractically full. One operator handles two machines so that after onemold has been poured the same is allowed to stand for an interval topermit the casting to set. During that interval the other machine is 55prepared for molding and the metal poured thereinto. By the time thesecond machine has been poured the casting in the first has practicallyset and the operator returns to it, manipulates suitable valves notshown for controlling the 60 supply of fluid pressure to the cylindersl3 and 20. Arrangements for such controls may be made as described inPatent No. 1,952,200, issued to JOhn Flammang', Percy L. Bowser andHerman Ernst, March 27, 1934. The cylinders l3 oper- 5 ate to draw apartthe mold sections 5 thereby freeing the outside of the casting. Thecylinder 20 withdraws the center core section 9. Upon completion of thewithdrawal the head 33 depresses the cross member 3| thereby with- 70drawing the locking pins from the side core sections as alreadydescribed. As soon as the operator is satisfied that the casting hascooled to a sufficient state of hardness he moves the two handles 23towards each other, thereby mov- 75 ing the side core sections inwardlyinto the space vacated by the section 9, separatingthe side sectionsfrom the interior oflthe casting and freeing the casting for removal.The casting isthen removed with a suitable pair of tongs and the fluidpressure valve manipulated to close I the mold sections and return thecore section 9, the side sections I having previously been separated bymeans of handles 23.

When a different casting is to be made the moldsection may be changed.That is the prescut mold may be removed and a new mold mounted in themachine. In order to assure accurate positioning of the mold sections,keys 42 are provided. Each key is recessed into the mold section 5 andinto its carrier 'II. If desired these keys may be permanently securedto the carriers. This provides simple means for insuring that the sidesections It shall be accurateiy positioned with respect to the base andwith respect to each other. M

It will be seen therefore that the invention provides a machine whichmay be handled rapidly in making a" large number of castings and inwhich automatic devices insure that the parts are accurately located sothat true castings are ll insured. Undue haste on the part of theoperator is also insured against by provision of theiatches 24. Thegates are so arranged so as to provide ample metal therein for shrinkageand at a temperature such as to hasten cooling of the I0 casting.

, While this invention has been described as embodied in a unitarydevice, it will be understood that individual features andsub-combinations of this device may be useful by themselves withoutreference to other features or the complete combination, and that theemployment of such individual features or sub-combinations iscontemplate-d by this invention and within the scope of the appendedclaims. 40

It is further obvious that various changes may be made, within the scopeof the appended claims, in the details of construction without departingfrom the spirit of this invention; it is understood, therefore, that theinvention is not limited to 4|! the specific details shown and/0rdescribed.

We claim: 7

1. In a piston mold of the character described having a matrix in whichthe piston is cast with the head up, a gate for the mold having an inletflared radially and an outlet into the matrix flared circumferentiallywith respect to the matrix.

2. In a molding machine of the character described, a base, a moldthereon, a sectional core for said mold comprising center and sidesections, said sections 'being constructed and arranged for withdrawalsuccessively with a succeeding section moving into the space vacated bya preceding section, and means other than the 00 parting faces of saidsections, positionable in the path of movement of the succeeding sectionfor locking said succeeding section against movement before thepreceding section has cleared said space. 66

3. in a molding machine of the character described, a base, a moldthereon, a sectional core for said mold comprising center and sidesections, said sections being constructed and arranged for withdrawalsuccessively with a suc- 70 ceeding section moving into the spacevacated by a preceding section, means other than the parting faces ofsaid sections, positionable in the path of movement of the succeedingsection for locking said succeeding sectio against move- 7 ment beforethe preceding section has cleared said space and means operating whensaid preceding section has been completely withdrawn to release saidlocking means.

4. In a molding machine of the character described, a base, a, moldthereon, a sectional core for said mold comprising center and sidesections, said sections being constructed and arranged for, withdrawalsuccessively with a succeeding section moving into the space vacated bya preceding section, and a latch for locking said succeeding sectionagainst movement before the preceding section has cleared said space,said preceding section moving in a path to engage and release said latchwhen completely withdrawn.

